HomeMy WebLinkAboutCT 05-15; LA COSTA OAKS NEIGHBORHOOD 3.1, 3.3-3.5; COMPLETION OF GRADING LOTS 75, 77, 78; 2010-11-04CT 05-i13
GEOCON
INCORPORATED
GEOTECHNI CAL u ENVIRONMENTAL I MATERIALS
Project No. 06105-52-24B
November2,2010
Revised November 4, 2010
CoiRich
4747 Morena Boulevard, Suite 100
San Diego, California 92117 5
Attention: Ms. Ten Shusterman
Subject: VILLAGES OF LA COSTA
THE OAKS NORTH, NEIGHBORHOOD 3.3 NORTH
- LOTS 75, 77, AND 78
S CARLSBAD, CALIFORNIA S
COMPLETION OF GRADING •. S
' References: 1. Update Geotechnicäl RepOrt Villages of La Costa - The Oaks North,
Neighborhood 3.3 North, Lots 1 through 18, 36 through 79, and 116 through
. 120, Carlsbad, California, prepared 'by Geocoñ Incorporated, dated May 7, 2008
(Project No. 06105-12-24).
2. Final Report of Testing and Observation Services Performed During. Site
Grading; VillOges of La COsta — .The Oaks North, Neighborhood 3.3 -- North,
- Lots 1 through 18, Lots 36-through 79 and Lots. 116 through 120 Carlsbad, S
California, prepared by Geocon Incorporated, dated November 14,2007 (Project
No. 06105-52-20). . .
.
Dear Ms. Shusterman:
S -
In accordance with the request of City of Carlsbad, we prepared this letter to confirm that the grading
'y of Lts 75, 77 and 78 of the subject development is c6mp1ete We performed testing and observation
,
ur vi9sàing the original grading operations as presented in the referenced report Recent regrading
praqoi included processing, moisture conditioning, and recompacting the subject pads We
obs'ed the compaction procedures and performed in-place density tests to evaluate the dry density
-and moisture content of-the, fill; material'. We performed in-place density tests in general conformance N
with ASTM Test Method D 6938 The results of the in-place dry density and moisture content tests
are summarized in Table I The results of the laboratory tests selected from the referenced report, are
summarized on Table II In general, the in-place dry density test results indicate that the fill soil has a
. dry density of least 90 percent of the laboratory maximum dry denity near to slightly above optimum
moisture content at the locations tested.
From a geotechrncal engineering standpoint, earthwork operations were performed in substantial
conformance with the referenced report and the building pads have been properly graded to receive
the planned improvements The concluions and recommendations presented in-the referenced reports
remain applicable for the development of the proje&. -.
S 6960 Flanders Drive • San Diego, California 92121-2974 U Telephone 858.558.6900 • Fax 858.558.6159
Should you have any questions regarding this letter, or if we may be of further service, please contact
the undersigned at your convenience.
Very truly yours,
-
GEOCON INCORPORATED
WE
'Shawn Foy "edon co Cn
SFW dmc top C
FC
(2/del) Addressee
(email) Col Rich Job Site
Attention: Mr. Steve Molina
Project No. 06105-52-24B - 2 - November 4, 2010
F -
S TABLEI -
SUMMARY OF FIELD DENSITY TEST RESULTS
- Elev. Plus - Field Field Field Req'd.-
or 3/4 Adj. Adj. Dry Moist. Re!. Re!.
/ Depth Curve Rock MDD OMC' Dens. Cont. Comp. Comp.
Test No. Date , - Location .
(ft) No. (°"°) (pci) (%) (pci)
RG ' 1 10/21/10 Lot 75. - 552- 18 30 145.9 5.5 135.4 8.9 93 90
RG 2 10/21/10 Lot 77
5 552 18 - 30 . 145.9 5.5 133.8 8.0 92 90
RG 3 10/21/10 Lot 78
5 552 .. 18 30 145.9 5.5 135.6 - 9.0 93 90
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Project No,. 06105-52-24B -
November 41 2010
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TABLE I
EXPLANATION OF CODED TERMS
-TEST SUFFIX
A, B, C,.. . : Retest of previous density test failure, following moisture conditioning and/or recompaction.
- STRIKE-OUT
Fill in area of density test failure was removed and replaced with properly compacted fill soil.
- PREFIX CODE DESIGNATION FOR TEST NUMBERS
AC -' ASPHALT CONCRETE B - BASE V CG - CURB AND GUTTER
JT - JOINT TRENCH SD - STORM DRAIN SG - SUB GRADE
SL. - SEWER LATERAL V SM - SEWER MAIN. SW - SIDEWALK V
WL - WATER LATERAL' WM - WATER MAIN
- CURVE NO. V V
V
V Corresponds to curve numbers listed in the summary of laboratory maximum dry density and optimum moisture content test results table for
selected fill soil samples encountered during testing -and observation. V V
- ROCK CORRECTION
For density tests with rock percentage greater than zero, laboratory maximum dry density and optimum moisture content were adjusted for rock
V
content. For tests with rock content equal to zero, laboratory maximum dry density and optimum moisture content values are unadjusted. V. -
-TYPE OFTEST V V V
V V V V
V
V SC: Sand Cone Test (ASTM D 1556)
V
V
NU: Nuclear Density Test (ASTM D 6938) V
V V
'OT: Other V
V
V V
V V
V
V V
- ELEVATION/DEPTH
V
V V
V V V V V
V
Test elevations/depths have been rounded to the nearest whole foot. V
V
V
Project No. 06105-52-24B V V V
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V V November 4, 2010
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TABLE II
SUMMARY OF LABORATORY MAXIMUM DRY DENSITY AND OPTIMUM MOISTURE CONTENT TEST RESULTS
ASTM D 1557
r Sample No Description Maximum Dry Density
(pci)
Optimum Moisture Content
(% dry weight)
18 Light reddish brown, Silty to Clayey, fine to coarse SAND 138.9 7.6